Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Cash flows from operating activities:
Net earnings	$ 78,668		$ 90,456
Depreciation and amortization	8,496		8,219
Amortization of net premiums on securities available-for-sale	10,601		9,523
Amortization of intangible assets	3,064	$ 3,176	4,746
Provision for credit losses	24,728	23,215	20,140
Gain on sale of foreclosed assets	0		(504)
Gain on sale of loans and leases	(712)	(119)	(245)
Gain on sale of premises and equipment	(560)		(6)
Loss (gain) on sale of securities	99		(8,110)
Gain on BOLI death benefit	(471)		(542)
Unrealized loss (gain) on derivatives and foreign currencies, net	202		(250)
Earned stock compensation	6,470		5,046
Loss on sale of PWEF leasing unit	0		720
Tax effect included in stockholders' equity of restricted stock vesting	0		(3,795)
Decrease in accrued and deferred income taxes, net	1,091		24,726
Decrease in other assets	661		5,756
Decrease (increase) in accrued interest payable and other liabilities	10,852		(23,722)
Net cash provided by operating activities	143,189		132,158
Cash flows from investing activities:
Net increase in loans and leases	(157,244)		(170,465)
Proceeds from sales of loans and leases	37,173		26,903
Proceeds from maturities and paydowns of securities available-for-sale	92,612		61,626
Proceeds from sales of securities available-for-sale	42,996		343,031
Purchases of securities available-for-sale	(248,187)		(52,236)
Net redemptions of Federal Home Loan Bank stock	3,969		2,460
Proceeds from sales of foreclosed assets	212		4,443
Purchases of premises and equipment, net	(1,944)		(2,896)
Proceeds from sales of premises and equipment	10,290		6
Proceeds from sale of leasing unit	0		138,809
Proceeds from BOLI death benefit	1,192		1,853
Net decrease (increase) of equipment leased to others under operating leases	114		(12,300)
Net cash (used in) provided by investing activities	(218,817)		341,234
Cash flows from financing activities:
Net increase (decrease) in noninterest-bearing deposits	131,170		(31,310)
Net increase (decrease) in interest-bearing deposits	329,605		(193,315)
Net decrease in borrowings	(445,203)		(68,483)
Common stock repurchased and restricted stock surrendered	(2,281)		(141)
Tax effect included in stockholders' equity of restricted stock vesting	0		3,795
Cash dividends paid	(60,833)		(60,906)
Net cash used in financing activities	(47,542)		(350,360)
Net (decrease) increase in cash and cash equivalents	(123,170)		123,032
Cash and cash equivalents, beginning of period	419,670		396,486
Cash and cash equivalents, end of period	296,500	$ 419,670	519,518
Supplemental disclosures of cash flow information:
Cash paid for interest	14,352		15,080
Cash paid for income taxes	2,834		15,773
Loans transferred to foreclosed assets	$ 78		$ 129